Buckle device

ABSTRACT

A buckle device which can ensure smooth unlocking over a long period of time at low cost. A button slope  66  is a curved surface opening toward a button  50  side with respect to an unlocking direction. Accordingly, the increasing amount of force of the button slopes  66  pressing abutted surfaces  86 A with respect to the amount of movement of the button  50  is small immediately after the button  50  started to be pressed, and frictional resistance between the button slopes  66  and the abutted surfaces  86 A can be thereby made smaller than before. Thus, wear of the abutted surfaces  86 A can be reduced or prevented. For example, even when coatings are applied to the abutted surfaces  86 A to reduce the frictional resistance between the button slopes  66  and the abutted surfaces  86 A so that the unlocking can be smoothly carried out, degree of dependence on the coatings for reducing the frictional resistance becomes lower than before so that the coatings can be kept long. As a result, the unlocking can be smoothly carried out over a long period of time.

TECHNICAL FIELD

[0001] The present invention relates to a buckle device, which, in aseat belt device for a vehicle, maintains a state in which a webbingbelt restrains the body of a vehicle occupant.

BACKGROUND ART

[0002] A seat belt device for restraining, by an elongated webbing belt,the body of a vehicle occupant who is seated in a seat of a vehicle,comprises a so-called buckle device. The buckle device comprises a case,and is locked by passing a latch through a hole formed in a tongue plateprovided at the webbing belt in a state in which the tongue plate isinserted into the case, so that the webbing belt is fastened to thevehicle occupant.

[0003] In order to release this locked state, a release button providedat the case is pressed. Button slopes having inclined surfaces areformed in the release button. When the release button is pressed andmoved relatively to the case, the latch abuts against the inclinedsurfaces of the button slopes. Further, the release button is moved evenmore in the state in which the latch abuts against the inclined surfacesof the button slopes, the latch moves along the inclined surfaces andthereby separates from the tongue plate, so that the lock of the tongueplate by the latch is released.

[0004] As described above, when the release button is moved in the statein which the latch abuts against the inclined surfaces of the buttonslopes, friction causes between the latch and the inclined surfaces ofthe button slopes. In order to reduce frictional resistance therebetweenso that the latch moves smoothly along the inclined surfaces of thebutton slopes, coatings are generally applied to the inclined surfacesof the button slopes and/or portions of the latch abutting against theinclined surfaces.

[0005] However, while the lock is repeatedly released, the coatings aredeteriorated by the friction. In the state in which the coatings aredeteriorated, the locking is released less smoothly than in the state inwhich the coatings are not deteriorated.

[0006] As a means for preventing the problem, the coatings may be simplythickened. However, the thickened coatings increase costs.

[0007] In view of the above facts, an object of the present invention isto obtain a buckle device which can ensure smooth unlocking over a longperiod of time at low cost.

DISCLOSURE OF THE INVENTION

[0008] In order to attain the above object, a buckle device of claim 1comprises: a device body into which a tongue plate is insertable, thetongue plate being provided at a webbing belt for restraining anoccupant body; a locking member, which is provided in the device bodysuch that the locking member is movable toward and away from the tongueplate inserted into the device body, and which engages with the tongueplate to lock the tongue plate inserted into the device body; and anunlocking member, which moves relatively to the device body due toreleasing operation from the outside of the device body, and on whichthe locking member slides at least during the relative movement andwhich presses the locking member with the relative movement so as tomove the locking member in a direction in which the locking memberseparates from the tongue plate; wherein each of abutting portions ofthe unlocking member, on which the locking member slides, comprisesplural inclined surfaces, which descend in a direction opposite to thedirection in which the unlocking member moves relatively to the devicebody when the locking member is pressed so as to protrude in thedirection in which the locking member is pressed, and which are sequentin the direction of the relative movement, and which relatively havelarger angles of inclination in the direction of the relative movement.

[0009] In a buckle device of claim 2 according to the present inventionof claim 1, the abutting portion comprises a curved surface formed by asequence of innumerable extremely minute inclined surfaces.

[0010] In a buckle device of claim 3 according to the present inventionof claim 2, an abutted portion of the unlocking member, the abuttingportion contacts, comprises at least one of a curved surface and aninclined surface, a portion of which contacting the abutting portionvaries with the relative movement.

[0011] In a buckle device of claim 4 according to the present inventionof claim 3, the unlocking member comprises: a press portion, which isprovided such that the press portion is slidable in the direction inwhich the tongue plate is inserted into the device body and in theopposite direction thereto, and which slides into the device body due toa pressing force along the insertion direction from the outside of thedevice body; a first urging member, which urges the locking membertoward the tongue plate inserted into the device body; and stoppers,which interfere with the unlocked locking member in a state in which thepress portion has not slid into the device body, so as to hold thelocking member at the unlocked position.

[0012] In a buckle device of claim 5 according to the present inventionof claim 4, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0013] In a buckle device of claim 6 according to the present inventionof claim 5, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0014] In a buckle device of claim 7 according to the present inventionof claim 3, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0015] In a buckle device of claim 8 according to the present inventionof claim 7, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0016] In a buckle device of claim 9 according to the present inventionof claim 3, the unlocking member comprises: a press portion, which isprovided such that the press portion is slidable in the direction inwhich the tongue plate is inserted into the device body and in theopposite direction thereto, and which slides into the device body due toa pressing force along the insertion direction from the outside of thedevice body; a first urging member, which urges the locking membertoward the tongue plate inserted into the device body; and stoppers,which interfere with the unlocked locking member in a state in which thepress portion has not slid into the device body, so as to hold thelocking member at the unlocked position.

[0017] In a buckle device of claim 10 according to the present inventionof claim 9, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0018] In a buckle device of claim 11 according to the present inventionof claim 10, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0019] In a buckle device of claim 12 according to the present inventionof claim 2, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0020] In a buckle device of claim 13 according to the present inventionof claim 12, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0021] In a buckle device of claim 14 according to the present inventionof claim 1, an abutted portion of the unlocking member, the abuttingportion contacts, comprises at least one of a curved surface and aninclined surface, a portion of which contacting the abutting portionvaries with the relative movement.

[0022] In a buckle device of claim 15 according to the present inventionof claim 14, the unlocking member comprises: a press portion, which isprovided such that the press portion is slidable in the direction inwhich the tongue plate is inserted into the device body and in theopposite direction thereto, and which slides into the device body due toa pressing force along the insertion direction from the outside of thedevice body; a first urging member, which urges the locking membertoward the tongue plate inserted into the device body; and stoppers,which interfere with the unlocked locking member in a state in which thepress portion has not slid into the device body, so as to hold thelocking member at the unlocked position.

[0023] In a buckle device of claim 16 according to the present inventionof claim 15, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0024] In a buckle device of claim 17 according to the present inventionof claim 16, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0025] In a buckle device of claim 18 according to the present inventionof claim 14, the locking member includes a latch, which passes through athrough-hole formed in the tongue plate so as to lock the tongue plate,and the device body comprises a holding member, which holds the latchsuch that the latch is slidable toward and away from the tongue platealong a thickness direction of the tongue plate inserted into the devicebody.

[0026] In a buckle device of claim 19 according to the present inventionof claim 18, the holding member has a second urging member, which urgesthe unlocking member in a direction opposite to the direction in whichthe unlocking member moves when the lock of the tongue plate isreleased.

[0027] In a buckle device of claim 20 according to the present inventionof claim 1, the unlocking member comprises: a press portion, which isprovided such that the press portion is slidable in the direction inwhich the tongue plate is inserted into the device body and in theopposite direction thereto, and which slides into the device body due toa pressing force along the insertion direction from the outside of thedevice body; a first urging member, which urges the locking membertoward the tongue plate inserted into the device body; and stoppers,which interfere with the unlocked locking member in a state in which thepress portion has not slid into the device body, so as to hold thelocking member at the unlocked position.

[0028] In accordance with a buckle device relating to the presentinvention of claim 1, when the locking member provided in the devicebody engages with the tongue plate in a state in which the tongue plateis inserted into the device body, the tongue plate is locked by thelocking member and restrained from moving in a direction in which thetongue plate is removed from the device body. Accordingly, the webbingbelt provided with the tongue plate becomes in a fastened state so thatan occupant body is restrained by the webbing belt.

[0029] When the unlocking member is operated from the outside of thedevice body in the locked state in which the locking member engages withthe tongue plate, and thereby moved relatively to the device body, theabutting portions of the unlocking member abut against and press thelocking member. The locking member moves, due to the pressing force, ina direction in which the locking member separates from the tongue plate,and thus, the lock of the tongue plate by the locking member is releasedso that the tongue plate can be removed from the device body.

[0030] In the buckle device of the present invention, each of theabutting portions of the unlocking member, on which the locking memberslides, comprises plural inclined surfaces being sequent in thedirection in which the unlocking member moves relatively to the devicebody when the locking member is pressed. The inclined surfaces descendin a direction opposite to the direction of the relative movement so asto protrude in the direction in which the locking member is pressed, andrelatively have larger angles of inclination in the direction of therelative movement and face to the direction opposite to the direction ofthe relative movement.

[0031] Thus, immediately after the unlocking member started the relativemovement, since the angle of inclination of the inclined surface formingthe abutting portion is small, the distance at which the locking membermoves due to the pressing force from the abutting portions is small.Thereafter, as the unlocking member relatively moves, the lockingdistance gradually increases and the distance at which the lockingmember moves gradually increases.

[0032] Since, in this manner, the amount of movement of the lockingmember is small immediately after the unlocking member started to moverelatively to the device body, the pressing force, the abutting portionsapply to the unlocking member at the time of starting to unlock, can bemade small. As a result, frictional resistance between the abuttingportions and the abutted portions at the time of starting to unlockbecomes small.

[0033] Therefore, even if coating or the like is applied to the lockingmember and/or the unlocking member in order to reduce the frictionalresistance between the abutting portions and the portions of the lockingmember contacting the abutting portions, degree of dependence on thecoating or the like for reducing the frictional resistance can be madesmall, and thus, deterioration of the coating or the like can beprevented or reduced.

[0034] Although the abutting portion has a structure including asequence of plural inclined surfaces in the present invention, theabutting portion is not limited to a planar surface in the presentinvention. In other words, since a curved surface is formed by asequence of innumerable extremely minute inclined surfaces which havedifferent angles of inclination from each other, even if the abuttingportion is a curved surface, such a structure does not contradict thestructure of the present invention according to claim 1.

[0035] The abutting portion of a buckle device relating to the presentinvention of claim 2 comprises a curved surface formed by a sequence ofinnumerable extremely minute inclined surfaces. When the abuttingportion comprises a curved surface in this manner, rate of change forthe angle of inclination along the direction, in which the unlockingmember moves relatively to the device body when the locking member ispressed, is small. Accordingly, the pressing force applied from theabutting portions (the unlocking member) to the locking member does notchange rapidly, and the locking member can be thereby moved smoothly.

[0036] In a buckle device relating to the present invention of claim 3,the abutted portion of the locking member corresponding to the abuttingportion of the unlocking member comprises an inclined surface or acurved surface, and the portion of the abutted portion contacting theabutting portion varies with the movement of the unlocking memberrelative to the device body. Therefore, the portion where the frictionbetween the abutting portion and the abutted portion causes basicallyvaries all the time during unlocking. Accordingly, not only specificportions of the abutting portion and/or the abutted portion wear, andthus, even when the above-described coating or the like is applied,deterioration of the coating can be prevented or reduced even more.

[0037] In accordance with a buckle device relating to the presentinvention of claim 4, the stoppers are provided at the unlocking member.For example, in a state in which the tongue plate is not inserted intothe device body, the stoppers interfere with the locking member so as tohold the locking member at the unlocked position.

[0038] When the tongue plate is inserted into the device body in thisstate to release the stoppers' interference with the locking member, thefirst urging member forming the unlocking member moves the lockingmember with the urging force thereof to engage the locking member withthe tongue plate. As a result, the tongue plate is locked.

[0039] When the press portion of the unlocking member is pressed in thestate in which the tongue plate is locked by the locking member, so thatthe unlocking member slides in the direction in which the tongue plateis inserted into the device body, the abutting portions move the lockingmember. Accordingly, the lock of the tongue plate is released, and thestoppers interfere with the locking member so as to hold the lockingmember at the unlocked position.

[0040] In accordance with a buckle device relating to the presentinvention of claim 5, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0041] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough-hole formed in the tongue plate so as to lock the tongue plate.

[0042] In accordance with a buckle device relating to the presentinvention of claim 6, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0043] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0044] In accordance with a buckle device relating to the presentinvention of claim 7, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0045] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough-hole formed in the tongue plate so as to lock the tongue plate.

[0046] In accordance with a buckle device relating to the presentinvention of claim 8, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0047] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0048] In accordance with a buckle device relating to the presentinvention of claim 9, the stoppers are provided at the unlocking member.For example, in a state in which the tongue plate is not inserted intothe device body, the stoppers interfere with the locking member so as tohold the locking member at the unlocked position.

[0049] When the tongue plate is inserted into the device body in thisstate to release the stoppers' interference with the locking member, thefirst urging member forming the unlocking member moves the lockingmember with the urging force thereof to engage the locking member withthe tongue plate. As a result, the tongue plate is locked.

[0050] When the press portion of the unlocking member is pressed in thestate in which the tongue plate is locked by the locking member, so thatthe unlocking member slides in the direction in which the tongue plateis inserted into the device body, the abutting portions move the lockingmember. Accordingly, the lock of the tongue plate is released, and thestoppers interfere with the locking member so as to hold the lockingmember at the unlocked position.

[0051] In accordance with a buckle device relating to the presentinvention of claim 10, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0052] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough-hole formed in the tongue plate so as to lock the tongue plate.

[0053] In accordance with a buckle device relating to the presentinvention of claim 11, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0054] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0055] In accordance with a buckle device relating to the presentinvention of claim 12, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0056] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough hole formed in the tongue plate so as to lock the tongue plate.

[0057] In accordance with a buckle device relating to the presentinvention of claim 13, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0058] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0059] In a buckle device relating to the present invention of claim 14,the abutted portion of the locking member corresponding to the abuttingportion of the unlocking member comprises an inclined surface or acurved surface, and the portion of the abutted portion contacting theabutting portion varies with the movement of the unlocking memberrelative to the device body. Therefore, the portion where the frictionbetween the abutting portion and the abutted portion causes basicallyvaries all the time during unlocking. Accordingly, not only specificportions of the abutting portion and/or the abutted portion wear, andthus, even when the above-described coating or the like is applied,deterioration of the coating can be prevented or reduced even more.

[0060] In accordance with a buckle device relating to the presentinvention of claim 15, the stoppers are provided at the unlockingmember. For example, in a state in which the tongue plate is notinserted into the device body, the stoppers interfere with the lockingmember so as to hold the locking member at the unlocked position.

[0061] When the tongue plate is inserted into the device body in thisstate to release the stoppers' interference with the locking member, thefirst urging member forming the unlocking member moves the lockingmember with the urging force thereof to engage the locking member withthe tongue plate. As a result, the tongue plate is locked.

[0062] When the press portion of the unlocking member is pressed in thestate in which the tongue plate is locked by the locking member, so thatthe unlocking member slides in the direction in which the tongue plateis inserted into the device body, the abutting portions move the lockingmember. Accordingly, the lock of the tongue plate is released, and thestoppers interfere with the locking member so as to hold the lockingmember at the unlocked position.

[0063] In accordance with a buckle device relating to the presentinvention of claim 16, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0064] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough-hole formed in the tongue plate so as to lock the tongue plate.

[0065] In accordance with a buckle device relating to the presentinvention of claim 17, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0066] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0067] In accordance with a buckle device relating to the presentinvention of claim 18, the device body comprises the holding member, forexample, provided therein, and the latch serving as the locking memberis thereby held such that the latch is slidable along a thicknessdirection of the tongue plate inserted into the device body.

[0068] When the tongue plate is inserted into the device body and thelatch slides toward the tongue plate, the latch passes through thethrough-hole formed in the tongue plate so as to lock the tongue plate.

[0069] In accordance with a buckle device relating to the presentinvention of claim 19, the holding member has the second urging member.The unlocking member is urged by the urging force of the second urgingmember in a direction opposite to the direction in which the unlockingmember moves when the lock of the tongue plate is released.

[0070] Accordingly, unless the unlocking member moves against the urgingforce of the second urging member, the lock of the tongue plate is notreleased, and the buckle device can be thereby prevented from beinginadvertently unlocked.

[0071] In accordance with a buckle device relating to the presentinvention of claim 20, the stoppers are provided at the unlockingmember. For example, in a state in which the tongue plate is notinserted into the device body, the stoppers interfere with the lockingmember so as to hold the locking member at the unlocked position.

[0072] When the tongue plate is inserted into the device body in thisstate to release the stoppers' interference with the locking member, thefirst urging member forming the unlocking member moves the lockingmember with the urging force thereof to engage the locking member withthe tongue plate. As a result, the tongue plate is locked.

[0073] When the press portion of the unlocking member is pressed in thestate in which the tongue plate is locked by the locking member, so thatthe unlocking member slides in the direction in which the tongue plateis inserted into the device body, the abutting portions move the lockingmember. Accordingly, the lock of the tongue plate is released, and thestoppers interfere with the locking member so as to hold the lockingmember at the unlocked position.

BRIEF DESCRIPTION OF THE DRAWINGS

[0074]FIG. 1 is a cross-sectional view of a buckle device in positionaccording to an embodiment of the present invention.

[0075]FIG. 2 is a cross-sectional view showing a state of the buckledevice locked by a locking member (a latch) in correspondence with FIG.1.

[0076]FIG. 3 shows a positional relationship between the locking member(the latch) and an abutting portion (a button slope) immediately afterstarting to unlock.

[0077]FIG. 4 shows another positional relationship between the lockingmember (the latch) and the abutting portion (the button slope) in astate in which the locking member (the latch) has moved more than thestate in FIG. 3.

[0078]FIG. 5 shows another positional relationship between the lockingmember (the latch) and the abutting portion (the button slope) in astate in which the locking member (the latch) has moved more than thestate in FIG. 4.

[0079]FIG. 6 shows another positional relationship between the lockingmember (the latch) and the abutting portion (the button slope) in astate in which the locking member (the latch) has moved more than thestate in FIG. 5.

[0080]FIG. 7 is an exploded perspective view of the buckle deviceaccording to the embodiment of the present invention.

[0081]FIG. 8 is a perspective view showing a modified example of theabutting portion (the button slope).

MOST PREFERRED EMBODIMENTS FOR IMPLEMENTING THE INVENTON Structure ofPresent Embodiment

[0082]FIG. 1 is a cross-sectional view of a buckle device 10 in positionaccording to an embodiment of the present invention, and FIG. 7 is anexploded perspective view of the buckle device 10.

[0083] As shown in FIG. 7, the buckle device 10 comprises asubstantially box-shaped case 12 which is made of a synthetic resin. Asshown in FIG. 1, one end of the case 12 in the longitudinal directionopens to form a slit opening 14 whose longitudinal direction is alongthe transverse direction of the case 12, and the other end of the case12 in the longitudinal direction opens to form an opening 16.

[0084] The case 12 contains a buckle body 20 inside. The buckle body 20comprises an anchor plate 26. The anchor plate 26 is formed by, forexample, bending a plate member at the center thereof in thelongitudinal direction so as to have a substantial U-shape, and theanchor plate 26 is contained inside the case 12 such that the openingend of the U-shape faces to the slit opening 14.

[0085] In the state in which the anchor plate 26 is contained in thecase 12, space between an upper plate 28 and a lower plate 30 of theanchor plate 26, the plates 28 and 30 being opposite to each other inthe vertical direction of the case 12, forms an insertion portion 34.Further, at a bottom portion of the anchor plate 26 bent in the U-shape,i.e., at the end of the anchor plate 26 on the opening 16 side, aslit-shaped insertion hole 32, whose longitudinal direction is along thetransverse direction of the anchor plate 26, is formed in correspondencewith a tongue plate 36.

[0086] A base end of the tongue plate 36 has a substantially slit-shapedinsertion hole through which an elongated webbing belt is inserted, anda leading end of the tongue plate 36 slides through the insertion hole32 into the space between the upper plate 28 and the lower plate 30,i.e., into the insertion portion 34.

[0087] As shown in FIG. 7, one end of a plate-shaped attachment piece 22is inserted into the space between the upper plate 28 and the lowerplate 30 from the opening end side of the anchor plate 26 bent in theU-shape, i.e., from the slit opening 14 side of the anchor plate 26. Theother end of the attachment piece 22 is fixed to a vehicle at a side ofa seat (e.g., driver seat or passenger seat) provided inside thevehicle. The one end of the attachment piece 22 inserted into the spacebetween the upper plate 28 and the lower plate 30 is fastened and fixedto at least one of the upper plate 28 and the lower plate 30 by rivets24, so that the anchor plate 26 is attached to the vehicle.

[0088] An ejector 38 is contained inside the anchor plate 26 such thatthe ejector 38 can slide along the longitudinal directions of the anchorplate 26 (the direction of arrow A in FIGS. 1 and 2 and the oppositedirection thereto). An eject spring 40 is disposed between the ejector38 and the attachment piece 22 to urge the ejector 38 toward theinsertion hole 32 side (the direction opposite to arrow A in FIGS. 1 and2).

[0089] Further, at both ends of the ejector 38 in the transversedirection, a pair of horn pieces 42 extend toward the attachment piece22 side (i.e., toward the slit opening 14 side of the case 12). Abutmentportions 46 are respectively formed near tips of the horn pieces 42. Incorrespondence with the abutment portions 46, protrusions are formed inthe anchor plate 26 so as to protrude into the insertion portion 34. Theprotrusions correspondingly interfere with the abutment portions 46 tolimit the slide of the ejector 38 within a predetermined range.

[0090] As shown in FIGS. 1 and 7, a button 50 forming an unlockingmember is disposed on the upper plate 28 of the anchor plate 26. Thebutton 50 is wholly formed in a substantially rectangular frame-shape ina plan view. The button 50 comprises an operation portion 52. Theoperation portion 52 has a pressing surface facing to the opening 16side. The pressing surface is pressed so that the button 50 can be movedto the slit opening 14 side.

[0091] A pair of outer plates 54 extend parallel with each other from aside of the operation portion 52 opposite to the pressing surface (i.e.,from the slit opening 14 side). Each of the outer plates 54 is formed ina substantial plate-shape whose thickness direction is along thetransverse direction of the anchor plate 26. The outer plates 54 areopposite to each other in the transverse direction of the anchor plate26.

[0092] Pawl pieces 62 extending toward the inner side are respectivelyformed at the outer plates 54. The pawl pieces 62 can engage withportions between the upper plate 28 and the lower plate 30 of the anchorplate 26 from outer sides of the anchor plate 26. In the state in whichthe pawl pieces 62 engage with the anchor plate 26, the button 50 cannotbe released from the anchor plate 26 and can be slid along thelongitudinal directions of the anchor plate 26 (the direction of arrow Ain FIGS. 1 and 7 and the opposite direction thereto).

[0093] A pair of inner plates 58 are respectively provided on innersides of the outer plates 54. The inner plates 58 extend parallel witheach other from the side of the operation portion 52 opposite to thepressing surface (i.e., from the slit opening 14 side) in the samemanner as the outer plates 54. Each of the inner plates 58 is formed ina substantial plate-shape whose thickness direction is along thetransverse direction of the anchor plate 26. The inner plates 58 areopposite to each other in the transverse direction of the anchor plate26.

[0094] Stoppers 64 are respectively formed on inner surfaces of theinner plates 58 (i.e., a stopper 64 is formed on a surface of one innerplate 58 on the opposite other inner plate 58 side, respectively). Inthe state in which the tongue plate 36 is not inserted into theinsertion portion 34, the stoppers 64 abut against a latch 84 serving asa locking member, which will be described later, so as to prevent thelatch 84 from moving in an engaging direction (the direction of arrow Bin FIGS. 1 and 7). Further, in the state in which the tongue plate 36 isinserted into the insertion portion 34 and the latch 84 engages with anengagement hole 88 of the tongue plate 36 (locked state: see FIG. 2),the stoppers 64 respectively abut against upper surfaces of abuttedpieces 86 of the latch 84 so as to prevent the latch 84 from moving in adisengaging direction (the direction opposite to arrow B in FIGS. 1 and7).

[0095] Button slopes 66 serving as abutting portions are respectivelyformed on the inner surfaces of the inner plates 58 on the operationportion 52 side with respect to the stoppers 64. The button slope 66descends toward the side opposite to the operation portion 52 (i.e., theslit opening 14 side) so as to protrude toward the side opposite to theanchor plate 26. A surface of the button slope 66 facing to the sideopposite to the anchor plate 26 gradually separates from the anchorplate 26 toward the operation portion 52 side.

[0096] When the button 50 moves in an unlocking direction (the directionof arrow A in FIGS. 1 and 7) in the locked state, the button slopes 66convert the pressing force to force which moves the latch 84 in thedisengaging direction (the direction opposite to arrow B in FIGS. 1 and7), and push abutted surfaces 86A serving as abutted portions of theabutted pieces 86 from lower sides thereof. Accordingly, the latch 84moves in the disengaging direction.

[0097] In this embodiment, the button slope 66 is not a planar surfacebut a curved surface opening toward the button 50 side with respect tothe unlocking direction. Therefore, the angle of inclination of thebutton slope 66 with respect to the unlocking direction varies dependingupon portions of the button slope 66 along the unlocking direction, anddecreases in the unlocking direction.

[0098] The above-described abutted surface 86A for contacting the buttonslope 66 is a curved surface projecting toward the button slope 66 side.The curvature of the abutted surface 86A is smaller than that of thebutton slope 66.

[0099] On the upper plate 28, a holding block 80 serving as a holdingmember, which straddles the inner plates 58, is disposed upright at aposition which is more inward than the outer plates 54 of the button 50.The holding block 80 has a pair of parallel holding plates 82, betweenwhich the latch 84 is disposed. The holding plates 82 prevent the latch84 from moving in the longitudinal directions of the anchor plate 26(the direction of arrow A in FIGS. 1 and 7 and the opposite directionthereto), and allow the latch 84 to move in the engaging and disengagingdirections (the direction of arrow B in FIGS. 1 and 7 and the oppositedirection thereto).

[0100] The latch 84 is formed in a substantial U-shape in a front view,and the abutted pieces 86 extend from upper ends thereof toward outersides in the transverse direction. Further, an engagement piece 90extends from the center of the latch 84 in the transverse directiontoward the anchor plate 26. When the tongue plate 36 is inserted intothe insertion portion 34 up to a predetermined position, the engagementpiece 90 passes through a through hole 92 formed in the upper plate 28of the anchor plate 26, engages with the engagement hole 88 of thetongue plate 36, and further passes through a through hole 94 (see FIG.2) formed in the lower plate 30.

[0101] A pair of plate spring pieces 96 serving as second urging membersextend from the holding block 80 toward the operation portion 52 of thebutton 50, and urge the button 50 toward the opening 16 side.Accordingly, when the operation portion 52 is pressed, appropriateresistance causes. Although the second urging members are formed by theplate spring pieces 96 in this embodiment, the second urging members maybe any unlocking members, i.e., any members that can urge the button 50toward the opening 16 side in this embodiment, and are not limited tospecific embodiments. Thus, coil springs may be used in place of theplate springs 96.

[0102] Leg portions 68 are respectively formed to protrude from ends ofthe above-described inner plates 58 on the slit opening 14 side towardthe anchor plate 26. The leg portions 68 respectively pass throughelongated holes 70 formed in the upper plate 28, and locate between theupper plate 28 and the lower plate 30. The longitudinal direction of theelongated hole 70 is along the direction in which the button 50 slides.When the button 50 slides, the leg portions 68 move along the elongatedholes 70. Similarly, when the leg portions 68 move along the elongatedholes 70, the button 50 slides.

[0103] The leg portions 68 passing through the elongated holes 70 locateon a track of the tongue plate 36 moving between the upper plate 28 andthe lower plate 30. When the tongue plate 36 has reached a predeterminedposition between the upper plate 28 and the lower plate 30, the ejector38 abuts against the leg portions 68. Further, when the tongue plate 36slides even more in this state, the leg portions 68 are pressed by theejector 38 to move.

[0104] Further, one end of a plate spring-shaped lock spring 98 formingan unlocking member as a first urging member is attached to the button50. The other end of the lock spring 98 abuts against an upper surfaceof the latch 84 to urge the latch 84 in the engaging direction (thedirection of arrow B in FIGS. 1 and 7).

Operation and Effect of the Present Embodiment

[0105] Next, operation and effect of the present embodiment will bedescribed.

[0106] In the buckle device 10 having the above-described structure, inthe state in which the tongue plate 36 is not inserted into theinsertion portion 34, the stoppers 64 of the button 50 abut against theabutted pieces 86 of the latch 84 from the lower side thereof, and thus,the latch 84 does not move in the engaging direction (the direction ofarrow B in FIGS. 1 and 7) by the urging force of the lock spring 98.

[0107] When the tongue plate 36 is inserted into the insertion portion34, the tongue plate 36 engages with the ejector 38 and presses it sothat the ejector 38 slides against the urging force of the eject spring40. Further, when the ejector 38 slides up to a predetermined position,the ejector 38 abuts against the leg portions 68 of the button 50, andpresses and moves the leg portions 68.

[0108] When the leg portions 68 move, the stoppers 64 of the button 50separate from the abutted pieces 86 of the latch 84. Therefore, thelatch 84 moves in the engaging direction (the direction of arrow B inFIGS. 1 and 7) by receiving the urging force of the lock spring 98, and,as shown in FIG. 2, the engagement piece 90 of the latch 84 passesthrough the through hole 92 of the upper plate 28 and engages with theengagement hole 88 of the tongue plate 36. The button 50 is pressed bythe plate spring pieces 96 and moved in the direction opposite to arrowA in FIGS. 1 and 7 so as to be in the locked state. In this state, thestoppers 64 of the button 50 abut against the abutted pieces 86 of thelatch 84 from the upper side thereof so as to prevent the latch 84 frommoving in the disengaging direction (the direction opposite to arrow Bin FIG. 2). In the locked state, the tongue plate 36 is restrained frombeing removed from the insertion portion 34 (the case 12) by theengagement piece 90 of the latch 84.

[0109] When the operation portion 52 of the button 50 is pressed in thisstate inside the case 12 in the direction of arrow A in FIG. 2, thestate in which the stoppers 64 and the abutted pieces 86 face to eachother is released first. When the state in which the stoppers 64 and theabutted pieces 86 face to each other is released, as shown in FIGS. 3 to6, the abutted surface 86A of the abutted piece 86 abutting against thebutton slope 66 is guided along the button slope 66 by the pressingforce therefrom against the urging force from the lock spring 98, whilethe abutted piece 86 moves upward, i.e., in the direction in which theabutted piece 86 separates from the tongue plate 36. The movement of theabutted pieces 86 allows the latch 84 to come out of the engagement hole88 first.

[0110] As shown in FIG. 1, when the latch 84 comes out of the engagementhole 88, it becomes possible that the tongue plate 36 comes out of theinsertion portion 34. When the ejector 38 receiving the urging force ofthe eject spring 40 presses the tongue plate 36 in this state, thetongue plate 36 comes out of the insertion portion 34. Further, when thepressing force applied to the operation portion 52 of the button 50 isreleased in this state, the button 50 returns, by the urging force ofthe plate spring pieces 96, to the former position where the pressingforce is not applied thereto. As a result, the stoppers 64 of the button50 abut against the abutted pieces 86 of the latch 84 again from thelower side thereof so that the latch 84 is held.

[0111] As described above, in this buckle device 10, the button slope 66is not a planar surface but a curved surface opening toward the button50 side with respect to the unlocking direction. The angle ofinclination of the button slope 66 with respect to the unlockingdirection decreases in the unlocking direction. Therefore, althoughfrictional resistance between the button slopes 66 and the abuttedsurfaces 86A is relatively high, in general, immediately after thebutton 50 (outer plates 54) started to be pressed, since the angle ofinclination of this button slope 66 decreases in the unlockingdirection, the amount of upward movement of the abutted surface 86A isrelatively small immediately after the button 50 (outer plates 54)started to be pressed.

[0112] Accordingly, the increasing amount of the force of the buttonslopes 66 pressing the abutted surfaces 86A with respect to the amountof movement of the button 50 is small, and the frictional resistancebetween the button slopes 66 and the abutted surfaces 86A can be therebymade smaller than before. Thus, wear of the abutted surfaces 86A can bereduced or prevented. For example, even when coatings are applied to theabutted surfaces 86A to reduce the frictional resistance between thebutton slopes 66 and the abutted surfaces 86A so that the unlocking canbe smoothly carried out, degree of dependence on the coatings forreducing the frictional resistance becomes lower than before so that thecoatings can be kept long. As a result, the unlocking can be smoothlycarried out over a long period of time.

[0113] Further, since the coatings do not need to be thickened in orderto keep the smooth unlocking operation over a long period of time, thecost is low.

[0114] As described above, in this buckle device 10, the abutted surface86A is a curved surface which projects toward the button slope 66 sideand the curvature of which is smaller than that of the abutted surface86A. Therefore, as shown in FIGS. 3 to 6, the portion of the abuttedsurface 86A contacting the button slope 66 when the abutted piece 86moves along the button slope 66 varies depending upon positions of theabutted piece 86 on the button slope 66. Accordingly, not only oneportion of the abutted surface 86A always contacts the button slope 66,and hence, even if the abutted surface 86A wears, the substantiallyentire abutted surface 86A wears uniformly. Thus, when a coating isapplied to the abutted surface 86A, the coating can wear uniformly, andearly considerable wear of one portion thereof can be prevented. As aresult, effect of the coating can be kept over a long period of time.

[0115] In this embodiment, the button slope 66 serving as an abuttingportion is a curved surface. However, as shown in FIG. 8, the buttonslope 66 may be formed by a sequence of planar inclined surfaces whichrelatively have smaller angles of inclination in the unlockingdirection.

INDUSTRIAL APPLICABILITY

[0116] As described above, the buckle device according to the presentinvention is available not only for a buckle device forming a seat beltdevice for a vehicle but also for a buckle device forming a seat beltdevice for things other than a vehicle, without being limited to aspecific embodiment of the seat belt device.

1. A buckle device comprising: a device body into which a tongue plateis insertable, the tongue plate being provided at a webbing belt forrestraining an occupant body; a locking member, which is provided insaid device body such that the locking member is movable toward and awayfrom the tongue plate inserted into said device body, and which engageswith the tongue plate to lock the tongue plate inserted into said devicebody; and an unlocking member, which moves relatively to said devicebody due to releasing operation from the outside of said device body,and on which said locking member slides at least during the relativemovement and which presses said locking member with the relativemovement so as to move said locking member in a direction in which saidlocking member separates from the tongue plate; wherein each of abuttingportions of said unlocking member, on which said locking member slides,comprises a curved surface, which descends in a releasing operationdirection which is the direction in which said unlocking member moveswhen the lock is released, so as to protrude in a release directionwhich is the direction in which said locking member moves when the lockis released, and whose angle of inclination with respect to thereleasing operation direction increases in a direction opposite to thereleasing operation direction.
 2. Canceled
 3. A buckle device accordingto claim 1, wherein an abutted portion of said unlocking member, saidabutting portion contacts, comprises at least one of a curved surfaceand an inclined surface, a portion of which contacting said abuttingportion varies with the relative movement.
 4. A buckle device accordingto claim 3, wherein said unlocking member comprises: a press portion,which is provided such that the press portion is slidable in thedirection in which said tongue plate is inserted into said device bodyand in the opposite direction thereto, and which slides into said devicebody due to a pressing force along the insertion direction from theoutside of said device body; a first urging member, which urges saidlocking member toward said tongue plate inserted into said device body;and stoppers, which interfere with the unlocked locking member in astate in which said press portion has not slid into said device body, soas to hold said locking member at the unlocked position.
 5. A buckledevice according to claim 4, wherein said locking member includes alatch, which passes through an engagement hole formed in said tongueplate so as to lock said tongue plate, and said device body comprises aholding member, which holds said latch such that said latch is slidabletoward and away from said tongue plate along a thickness direction ofsaid tongue plate inserted into said device body.
 6. A buckle deviceaccording to claim 5, wherein said holding member has a second urgingmember, which urges said unlocking member in a direction opposite to thedirection in which said unlocking member moves when the lock of saidtongue plate is released.
 7. A buckle device according to claim 3,wherein said locking member includes a latch, which passes through anengagement hole formed in said tongue plate so as to lock said tongueplate, and said device body comprises a holding member, which holds saidlatch such that said latch is slidable toward and away from said tongueplate along a thickness direction of said tongue plate inserted intosaid device body.
 8. A buckle device according to claim 7, wherein saidholding member has a second urging member, which urges said unlockingmember in a direction opposite to the direction in which said unlockingmember moves when the lock of said tongue plate is released.
 9. A buckledevice according to claim 1, wherein said unlocking member comprises: apress portion, which is provided such that the press portion is slidablein the direction in which said tongue plate is inserted into said devicebody and in the opposite direction thereto, and which slides into saiddevice body due to a pressing force along the insertion direction fromthe outside of said device body; a first urging member, which urges saidlocking member toward said tongue plate inserted into said device body;and stoppers, which interfere with the unlocked locking member in astate in which said press portion has not slid into said device body, soas to hold said locking member at the unlocked position.
 10. A buckledevice according to claim 9, wherein said locking member includes alatch, which passes through an engagement hole formed in said tongueplate so as to lock said tongue plate, and said device body comprises aholding member, which holds said latch such that said latch is slidabletoward and away from said tongue plate along a thickness direction ofsaid tongue plate inserted into said device body.
 11. A buckle deviceaccording to claim 10, wherein said holding member has a second urgingmember, which urges said unlocking member in a direction opposite to thedirection in which said unlocking member moves when the lock of saidtongue plate is released.
 12. A buckle device according to claim 1,wherein said locking member includes a latch, which passes through anengagement hole formed in said tongue plate so as to lock said tongueplate, and said device body comprises a holding member, which holds saidlatch such that said latch is slidable toward and away from said tongueplate along a thickness direction of said tongue plate inserted intosaid device body.
 13. A buckle device according to claim 12, whereinsaid holding member has a second urging member, which urges saidunlocking member in a direction opposite to the direction in which saidunlocking member moves when the lock of said tongue plate is released.14. Canceled
 15. Canceled
 16. Canceled
 17. Canceled
 18. Canceled 19.Canceled
 20. Canceled